backends: add a new "none" backend

It can only be used for projects that don't have any rules at all, i.e.
they are purely using Meson to:

- configure files
- run (script?) tests
- install files that exist by the end of the setup stage

This can be useful e.g. for Meson itself, a pure python project.

1 files changed, 6 insertions, 2 deletions

diff --git a/mesonbuild/mtest.py b/mesonbuild/mtest.py
index e1c6a21b7..768502384 100644
--- a/mesonbuild/mtest.py
+++ b/mesonbuild/mtest.py
@@ -43,7 +43,7 @@ import xml.etree.ElementTree as et
 from . import build
 from . import environment
 from . import mlog
-from .coredata import major_versions_differ, MesonVersionMismatchException
+from .coredata import MesonVersionMismatchException, OptionKey, major_versions_differ
 from .coredata import version as coredata_version
 from .mesonlib import (MesonException, OrderedSet, RealPathAction,
                        get_wine_shortpath, join_args, split_args, setup_vsenv)
@@ -2099,7 +2099,11 @@ def run(options: argparse.Namespace) -> int:
     setup_vsenv(b.need_vsenv)
 
     if not options.no_rebuild:
-        if not (Path(options.wd) / 'build.ninja').is_file():
+        backend = b.environment.coredata.get_option(OptionKey('backend'))
+        if backend == 'none':
+            # nothing to build...
+            options.no_rebuild = True
+        elif backend != 'ninja':
             print('Only ninja backend is supported to rebuild tests before running them.')
             # Disable, no point in trying to build anything later
             options.no_rebuild = True